Terminals may be divided into mobile/portable terminals and stationary terminals according to mobility. Mobile terminals may be divided into handheld terminals and vehicle mounted terminals according to whether or not a user can directly carry the terminal.
The functions of the mobile terminals are diversified. For example, the mobile terminals may include functions such as data and voice communication, photographing and filming through a camera, voice recording, playback of music files through a speaker system and output of images or video on a display. Some mobile terminals may further perform an electronic gaming function or multimedia player function. In particular, new mobile terminals may receive multicast signals for providing visual content such as broadcasts, video or television programs.
As the functions of the terminals are diversified, the terminals are implemented in the form of multimedia players having complex functions such as photographing or filming, playback of music or video files or reception of games and broadcast programs.
In order to support and increase the functions of the terminals, improvement of the structure and/or software of the terminals may be considered.
Meanwhile, various methods of using content such as video, music, and photos, which has utilized on a smartphone, through a display device such as a TV have been developed. For example, while YouTube video may be played on a TV, a computer screen may be output.
At this time, there is a need for various methods of conveniently and efficiently controlling the screen states of a plurality of external devices while the screens of the plurality of external devices are output on a display device.